1. Field of the Invention
The present invention concerns a hydrokinetic coupling apparatus, notably for a motor vehicle, of the type described and depicted for example in the document WO-A-93/13339.
2. Description of Related Art
This document describes and depicts a hydrokinetic coupling apparatus, notably for a motor vehicle, of the type having:
a casing provided with a wall, of transverse orientation overall, able to be connected with respect to rotation to a driving shaft; PA1 a turbine wheel fixed with respect to rotation to a hub able to be connected with respect to rotation to a driven shaft; PA1 a lock-up clutch, acting between the turbine wheel and the transverse wall, which has, arranged axially from front to rear between the turbine wheel and the transverse wall: PA1 a damper plate, fixed with respect to rotation to a turbine wheel, in the form of an annulus with a roughly transverse orientation and which has at its external periphery an annular portion, of roughly axial orientation, which circumferentially guides and holds circumferentially acting elastic members, and which has areas, of roughly transverse orientation, of abutment for the circumferential ends of the elastic members; PA1 a piston in the form of an annulus, of transverse orientation overall, movable axially and connected with respect to rotation to the casing; PA1 and at least one flat annular friction disc, of roughly transverse orientation, which carries, on its front and rear opposite faces, two annular friction linings which are able to clamped axially by the piston between respectively itself and the opposite internal face of the transverse wall of the casing, the friction disc having at its external periphery drive lugs which extend axially towards the rear inside the peripheral annular portion of the damper plate in order each to be received between the circumferential ends of two consecutive circumferentially acting elastic members, and which is able to move axially with respect to the damper plate. PA1 the tongues are coupled by their first ends to a first one of the two elements which they connect with respect to rotation, by means of a drive washer common to all the tongues and which is coupled to this first element, and the intermediate friction disc is driven in rotation by the common drive washer; PA1 the drive washer can be distinct from the tongues or be in a single piece with them; PA1 the external radial periphery of the common drive washer has a ferrule of roughly axial orientation having at least one notch through which there extends, radially inwards, a drive lug belonging to the intermediate friction disc; PA1 the ferrule of the common drive washer has a series of notches distributed angularly in a regular manner, through each of which there extends, radially inwards, a corresponding drive lug in a series of lugs belonging to the intermediate friction disc; PA1 each notch is open axially in the axial end edge of the ferrule of the common drive washer; PA1 each drive lug is received with circumferential clearance in a corresponding notch in the ferrule of the common drive washer; PA1 each drive lug of the intermediate friction disc lies in the plane of the disc; PA1 the ferrule of the common drive washer is an axially oriented cylindrical ferrule; PA1 the ferrule of the common drive washer is a frustoconical ferrule; PA1 the common drive washer is coupled to the first element by gluing or welding or riveting; PA1 the common drive washer is coupled to the transverse wall of the casing; PA1 the front and rear friction discs each have at least one drive lug which extends radially outwards in order to be received in a notch in an axially oriented cylindrical annular skirt connected with respect to rotation to the turbine wheel; PA1 the front and rear friction discs each have a series of drive lugs distributed angularly in a regular manner in order to be received in corresponding notches in an axially oriented cylindrical annular skirt connected with respect to rotation to the turbine wheel; PA1 each notch is axially open; PA1 each drive lug extends in the plane of its friction disc; PA1 one of the front or rear friction discs has at least one drive lug which extends radially outwards in order to be received in a notch in an axially oriented cylindrical annular skirt connected with respect to rotation to the turbine wheel, and the other one of the rear and front friction discs has at least one drive lug which cooperates with a driving lug of said at least one disc; PA1 the drive lug of said other disc extends radially outwards and then axially in the direction of the other disc; PA1 the drive lug of said other disc is angled at 90.degree., and the drive lug of said disc extends in the plane of this disc; PA1 the drive lugs of the front and rear friction discs are angled twice so that their free end portions, radially external and of transverse orientation, are substantially coplanar; PA1 one of the front or rear friction discs has at least one drive lug angled at 90.degree. which extends radially outwards and then axially in the direction of the other disc opposite a drive lug which extends radially outwards from the periphery of the other one of the rear or front friction discs and whose free end extends radially in a notch formed in an annular cylindrical skirt, of roughly axial orientation, connected with respect to rotation to the turbine wheel. PA1 the lock-up clutch has a torsion damper interposed between the turbine wheel and the piston, and the said skirt belongs to an input part of the torsion damper.
In the document FR-A-2.634.849, the lock-up clutch has a set of flat annular parallel friction discs, of roughly transverse orientation, which is able to be clamped axially by the piston between effectively itself and the opposite internal face of the transverse wall of the casing and which includes on the one hand two radially external front and rear discs which are here connected with respect to rotation directly to the turbine wheel and on the other hand a radially internal intermediate disc which is disposed axially between the front and rear discs and which is connected with respect to rotation to the piston, annular friction linings being interposed between the opposite annular faces of the friction discs, the piston and the internal face of the transverse wall. As a result the solution is noisy.